Gas engine



Jme 29,1926.

2 hee'CS--Sheet 1 Y Filed April 18, 1922 June 29 192e. 1,590,940

/F. N. HALLETT GAS ENGINE Filed April 18, 1922 42A Shees-Sheet 3 76 79 jig-k aune/wkn 71"'607 ly Hal/e# Patented June 29, 19276.

rnnnfnenannnrr, on sna'rnn, Wasnixeox.

" GASYENGINE. Y

application sied Aprilia, 13 2'2. serial im. 554,913;

This invention relates'tov an improvement vin explosive engines, wherein aY plurality ofmovable pistons areprovided in each cy'lm'-/ der, the relative movement of the pistons being timed to insure an effective intake, compression, and firing of the compressed gases, the relative movements of the pistons,

on the exhaust stroke causing said pistons to so approach each other as to practically Clear all exhaust gases from the cylinder.

The invention in the preferred Aform is illustrated in the accompanying drawings, in which:

Fig. 1 is a view in elevation, partly in section, illustrating the improved construction. s

Figs. 2, 3, et, and 5 are diagrammatic views, illustrating the differentv operative positions of the pistons. Y

The improved engine is made up of any usual or preferred number of cylinders 1, in each of which there is arranged a lower piston 2 and an upper piston 3. These pistons have the usual piston rings 1, and aside fromthe details hereinafter specifically described, may be of any desired construction.

The lower pistons 2 are connected by the usual connecting rods 5 with the throws 6 of the main crank shaft 7, there being' an auxiliary crank shaft 8 mounted in the upper end of the cylinder block having throws 9, to which, by connecting rods 10, the upper pistons are connected. Y

The forward end of the cylinder block is provided with a cover plate 11, forming a gear housing 12, and in this housing there is mounted on the main crank shaft 7, a chain sprocket 13, and on the tauxiliary crank shaft 8, a chain sprocket 14. The chain gear 13 is so proportioned to the chain sprocket 14 that inthe operation of the parts, these sprockets, connected by a chain 15, insure that the main crank shaft 7 makes two complete revolutions to each single revr olution of the auxiliary crank shaft. A piston controlled exhaust port 16 is provided for each cylinder, there being an exhaust passage 17 in the upper piston 3 of each cylinder, which exhaust passage opens through the operative face of the piston. A piston cont-rolled inlet Yport 18 is formed in each cylinder, and an inlet passage 19 controlled by a downwardly opening valve 2O is provided in each upper piston 3. The valve 20 is normally closed under spring pressure, as indicated n Fig. 2'to prevent the escape of Athe charge in the cylinder through thefinlct passage-19 during the compression, expansion, or'exhaust stroke', as the'passage 19 is open tothe intake during portions of these strokes.

ldfith the parts thus constructed and arranged, and assumingthe respective pistons to be in the position indicated in Fig. 2, it will ,be noted that said pistons have ap preached so closely together that practically no 'space exists therebetween and thus, in this position, which is the exhaust position, a complete scavenging of the cylinder will be had, it being noted that at this time the exhaust passage 17 of the upper piston is in registry with the exhaust port 16. Through the yindicated movements of the pistons, as seen from the arrows, the pistons then start to move apart, and as the inlet passage 19 registers with the inlet port 18, the exhaust port 16 having been closed in the meantime, by the passage 17 rising beyond said port, a fresh charge of gas isadmitted between the pistons. The complete inlet stroke is indicated in Fig.' 2. The pistons then approach each other, but as the lowerpiston 2 is moving twice as fast as the upper piston 3, the latter will have made one fourth of its complete stroke, that is, one half of its inward movement, while the former is making a complete inward movement. This is the compression -stroke, and as this stroke of the piston 2 is completed, the piston 3, having completedv only one half its stroke, will reach such position that there willy be afforded a firing chamber 21 between the pistons, in which the com? pressed gases are fired. On the next stroke of the pistons, they will have approached each other as indicated in Fig. 2 for the exhaust stroke.' This result is again of course through the ydifference in the speed of the respective pistons. i

It will of course be understood that other means than the chain connector may be utilized for driving the auxiliary crank shaft from the main crank shaft, the essential requirement being thatthe speed of the main or lower piston be twice that of the auxiliary or upper piston, and that these pistons be( so timed as to alternatelyl form and eliminate a firing chamber.

Claims:

1. In an explosive engine, a cylinder, a

main crank shaft, an auxiliary crank shaft,y

los y upon the crank shafts, an upper piston connected to the auxiliary crank shaft, a lower piston connected to the main crank shaft, a chain connecting said chain gears, an eX- haust port in the cylinder, an inlet port in the cylinder, an exhaust passage in the uprper piston leading through the operative face thereof, and an inlet passage in the up-V per piston leading through the operativ face thereof.

2. An explosive engine7 including a cylinder, a inain crank shaft, au auxiliary crank shaft at the upper endV of the cylinder, a

piston connected to the' main crank shaft, a piston connected tothe auxiliary crankshaft and formed with an exhaust passage and a valve controlled inlet passage, said cylinder being formed with inlet and exhaust passages for cooperating at predetermined intervals with the passages in the piston, and

connecting` means between the shafts for driving the auxiliary shaft tvv-ice as fast as the inain crank shaft.Y

In testimony Whereofhe aixeshis signature.

FRED NQHALLETT.' l 

